Low density parity check (LDPC) coding techniques are gaining increasing popularity, and have been accepted for numerous communication standards, e.g., IEEE 802.11 (Wi-Fi™) WiMAX™, Long Term Evolution (LTE), Digital Video Broadcast (DVBc2), Data Over Cable Service Interface Specification (DOCSIS3.1), etc.
LDPC coding is a type of block coding. On the encode side, an encoder adds m parity (redundant) bits to every k information bits to form n=k+m coded bits. On the decode side, a decoder extracts k information bits from n coded bits using m parity check equations. The code rate is defined as k/n.
LDPC coding, like all forward error correction (FEC) coding techniques, uses extra information carried in the redundant bits to recover the lost or damaged information bits. In other words, an LDPC code word sends more “information” than the original information bits and “inter-connects” the original information with the redundancy information so that the decoder can recover lost or damaged original information bits. The recovery ability of the coding used is defined as the coding strength.